Objective. To study the genes in the mouse background which predispose to the development of collagen-induced arthritis (CIA).
Methods. T cell receptor P transgenic (TCRPL)mice that have a T cell repertoire that predisposes to the development of CIA were used. Classic genetic studies and microsatellite gene mapping were done in (SWR-PL X DBA/l)F, hybrid mice.Results. Besides TCRP, major histocompatibility complex class 11, and Igh-C, at least 2 other genes are absolutely required for CIA development in these mice. A strict association of CIA with the presence of functional complement C5 allele (Hc') was found, suggesting that Hc' or a closely linked gene might be one of these essential genes.Conclusion. This study provides new evidence of the pathogenetic role of complement C5 in CIA. Furthermore, these transgenic mice may facilitate molecular identification of other genes that predispose to CIA.Collagen-induced arthritis (CIA) is a chronic inflammatory arthropathy considered to be an experimental model of rheumatoid arthritis (RA). CIA develops in mice, rats, and primates after immunization with native type I1 collagen (CII) in adjuvant (1-3). Although the precise mechanisms by which CIA develops arc not known, several findings indicate that the disease is due to autoreactivity to CII (for review, see ref. 4). Both cellular and T cell-dependent humoral anti-CII immune responses are important for the pathogenesis of the Supported by Swiss National Science Foundation grants .